These are some great DIY projects that you can do for cheap.

This document is aimed at the Arduino developers, radio experimenters, hobbyists and anyone interested in building a receiver based on the Si473X IC family from Silicon Labs. This project is about an ...

Optiboot (an older version) is installed by default on the Arduino Uno and (as of 2018) official Arduino Nano boards. It can be installed on all older mega8, 168 or 328 based Arduinos. As of 2019, ...

Abstract: Pyroelectric infrared (PIR) sensors are widely used as a simple but powerful people presence triggers, e.g., automatic lighting systems. In particular, by alternating the effective ...

Abstract: This paper evaluates the development of a Low-cost security system using small PIR (Pyroelectric Infrared) sensor built around a microcontroller. The low-power PIR detectors take advantage ...